Conventional semiconductor devices can be formed on various types of semiconductor substrates. For example, some conventional semiconductor devices can be formed using bulk silicon substrates, which generally represent blocks of silicon. As a particular example, various areas of a bulk silicon substrate can be doped and contacts can be fabricated over the bulk silicon substrate to form transistors in a semiconductor device. Other integrated circuits could also be formed in and over the bulk silicon substrate in the semiconductor device.
Other conventional semiconductor devices can be formed using silicon-on-insulator (SOI) substrates. A silicon-on-insulator substrate generally refers to a layered silicon-insulator-silicon substrate. Integrated circuits are generally formed in and over a portion of the silicon, where that portion is located above an insulator layer in the silicon-on-insulator substrate.
One specific type of silicon-on-insulator substrate is a silicon-on-nothing (SON) substrate, which generally refers to a layered silicon-nothing-silicon substrate. The “nothing” in the silicon-on-nothing substrate often represents an air pocket in the substrate. In other words, the silicon-on-nothing substrate is a type of silicon-on-insulator substrate that uses air as the insulating material. Integrated circuits are generally formed in and over a portion of the silicon, where that portion is located above the air pocket in the silicon-on-insulator substrate.